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Biomedical subjects

M Nakane

Publications and source records attributed to M Nakane.

At least 109 records · Page 6Linked to original sources
PubMed1989

[A case of retroperitoneal liposarcoma].

We reported a case of retroperitoneal well differentiated liposarcoma, which consisted of lipoma-like type and sclerosing type. The latter was represented as solid density tumor on CT, which was difficult to differentiate from undifferentiated liposarcoma and other soft tissue tumors. Angiographically, ureteral artery developed and became a main feeder.

Aged↗
PubMed1988

Molecular cloning of a cDNA coding for 70 kilodalton subunit of soluble guanylate cyclase from rat lung.

A complementary DNA clone corresponding to the 70 kDa subunit of soluble guanylate cyclase (EC 4.6.1.2) of rat lung has been isolated. The primary structure of the cDNA consisted of 3063 nucleotides including a 1857-nucleotide coding region for 619 amino acids, and the calculated molecular weight was 70476. Blot hybridization of total poly(A)+RNAs from rat tissues detected a mRNA of about 3.4 kilobases. The amount of mRNA was abundant in lung, cerebrum and cerebellum, moderate in heart and kidney, and low in liver and muscle. Southern blot analysis of high molecular weight genomic DNA from rat liver indicated the presence of one gene in the rat haploid genome. The amino acid sequence of the 70 kDa subunit has partial homology with particulate guanylate cyclase from sea-urchin sperm, and protein phosphatase inhibitor I.

Amino Acid Sequence↗
PubMed1988

Hypolipidemic effect of NS-1 and other related drugs in rhesus monkeys.

NS-1, 4-[2-(4-isopropylbenzamido)ethoxy]benzoic acid, is a novel chemical compound which has been found to be a potent hypolipidemic agent in rhesus monkeys. Significant reductions in serum cholesterol and phospholipids were observed in normolipidemic monkeys following oral doses of 30-300 mg/kg/day. A dose of 300 mg/kg/day for 28 days lowered serum cholesterol and phospholipid levels by 49% and 41%, respectively. NS-1 was more potent than clofibrate, clinofibrate, simfibrate, bezafibrate, gemfibrozil, nicomol and probucol in hypolipidemic activity in the same model. Lipoprotein analysis showed that NS-1 reduced low density lipoprotein much more than high density lipoprotein. The results suggest that NS-1 may have hypolipidemic activity in hyperlipidemic patients.

Animals↗
PubMed1987

Blood coagulation abnormalities in Fischer strain rats bearing tumors.

This study reports an unusual subpopulation of rats bearing transplanted tumors approximately 50% of the total and apparently unrelated to the presence of metastases, that exhibited shortened bleeding times despite reduced platelet numbers and/or fibrinogen levels. The remaining rats exhibited the expected inverse relationships between bleeding time and platelet numbers and/or fibrinogen level. Tumors were hepatomas and squamous cell carcinomas initially induced in the Fischer strain of rats and carried by passage through tissue culture or syngenic recipient animals.

Animals↗
PubMed1987

Expression and characterization of hydroxyindole O-methyltransferase from a cloned cDNA in Chinese hamster ovary cells.

We have used two kinds of expression systems to test whether the cloned cDNA encoding hydroxyindole O-methyltransferase (HIOMT) of the bovine pineal gland was functional or not. First, when mRNA was synthesized in vitro by the SP6 system and injected into Xenopus oocytes, the enzymatic activity was expressed in the oocytes. Second, the cloned cDNA was recombined to a vector under the control of the simian virus 40 early promoter and transfected to Chinese hamster ovary (CHO) cells. The enzymatic activity of the crude supernatant of transfected cells (CHO-HT2) reached to 400 pmol melatonin formed per min per mg of protein, which value was approximately 9% of that of bovine pineal supernatant. The amounts of enzyme protein estimated by immunoblotting were proportional to the enzymatic activity in both CHO and pineal gland. The content of HIOMT protein was 8- to 30-fold larger in pineal gland compared to CHO cells. On the other hand, the content of mRNA encoding the enzyme measured by dot hybridization with [32P]cDNA, was in the same range in both CHO cells and pineal glands. These data suggest that the 11-fold higher enzymatic activity in pineal gland is due to an accumulation of the enzyme protein, not to a high level of the mRNA and also indicate that the cloned cDNA can express an intact hydroxyindole O-methyltransferase enzyme in CHO cells.

Acetylserotonin O-Methyltransferase↗
PubMed1986

Soluble guanylate cyclase from rat lung exists as a heterodimer.

The soluble form of guanylate cyclase (EC 4.6.1.2) from rat lung has been purified to homogeneity by a one-step immunoaffinity chromatographic procedure. The purified soluble guanylate cyclase has specific activities of 432 and 49.1 nmol of cyclic GMP formed per min/mg protein with manganese and magnesium ions as a cofactor, respectively. This represents a purification of approximately 2,000-fold with a 50% recovery. The native enzyme has a molecular weight of 150,000 and a Stokes radius of 4.8 nm as determined on Spherogel TSK-G3000SW gel permeation chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis results in two protein-staining bands with molecular weights of 82,000 and 70,000. The purified soluble guanylate cyclase was also subjected to native polyacrylamide gel electrophoresis, isoelectric focusing electrophoresis, ion exchange chromatography, and GTP-agarose affinity chromatography. These additional purification procedures confirmed the presence of a single protein peak coincident with enzyme activity. The two subunits separated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis were shown to have different primary structures by immunoblotting with monoclonal and polyclonal antibodies prepared against purified soluble guanylate cyclase and by peptide mapping with papain or Staphylococcus aureus V8 protease treatment. These data demonstrate that soluble guanylate cyclase purified from rat lung is a heterodimer composed of 82,000- and 70,000-dalton subunits with different primary structures.

Animals↗
PubMed1986

Co-purification of an atrial natriuretic factor receptor and particulate guanylate cyclase from rat lung.

An atrial natriuretic factor (ANF) receptor from rat lung was solubilized with Lubrol-PX and purified by sequential chromatographic steps on GTP-agarose, DEAE-Sephacel, phenyl-agarose, and wheat germ agglutinin-agarose. The ANF receptor was enriched 19,000-fold. The purified receptor has a binding profile and properties that correspond to the affinity and specificity found in membranes and crude detergent extracts. Polyacrylamide gel electrophoresis of the purified preparation in the presence of sodium dodecyl sulfate and dithiothreitol showed the presence of one major protein band with a molecular mass of 120,000 daltons. When purified preparations were incubated with 125I-ANF, then cross-linked with disuccinimidyl suberate, the 120,000-dalton protein was specifically radiolabeled. This high affinity binding site for ANF co-purified with particulate guanylate cyclase. Particulate guanylate cyclase was purified to a specific activity of 19 mumol cyclic GMP produced/min/mg of protein utilizing Mn-GTP as substrate. This represented a 15,000-fold purification compared to the initial lung membrane preparation with Lubrol-PX. Gel permeation high performance liquid chromatography and glycerol density gradient sedimentation studies of the purified preparation also resulted in co-migration of specific ANF binding and guanylate cyclase activities. The co-purification of these activities suggests that both ANF binding and guanylate cyclase activities reside in the same macromolecular complex. Presumably ANF binding occurs at the external membrane surface and cyclic GMP synthesis at the internal membrane surface of this transmembrane glycoprotein.

Animals↗
PubMed1985

Pharmacological actions of SQ 29,548, a novel selective thromboxane antagonist.

SQ 29,548, [1S-[1 alpha,2 beta (5Z),3 beta,4 alpha]-7-[3-[[2-[(phenylamino) carbonyl]hydrazino]methyl]-7-oxabicyclo[2.2.1] hept-2-yl]-5-heptenoic acid, and the racemic modification, +/- SQ 29,548, were identified as active inhibitors of human platelet aggregation induced by arachidonic acid, collagen, epinephrine (2 degrees phase) and the thromboxane A2 mimics, 9,11-azo prostaglandin (PG) H2 and 11,9-epoxymethano PGH2. SQ 29,548 did not inhibit aggregation induced by ADP, and it did not prevent PGD2 from inhibiting ADP-induced platelet aggregation. Inhibition of platelet function by +/- SQ 29,548 was not associated with inhibition of cyclooxygenase or thromboxane synthetase or with changes in platelet cyclic AMP. In guinea-pig trachea and rat aorta, +/- SQ 29,548 competitively antagonized the activity of 9,11-azo PGH2 with pA2 values of 7.8 and 8.4, respectively. The chiral compound, SQ 29,548 competitively antagonized contractions of guinea-pig tracheal spirals caused by 11,9-epoxymethano PGH2 with a pA2 value of 9.1. The +/- SQ 29,548 competitively antagonized tracheal responses to 11,9-epoxymethano PGH2 and PGD2 with pA2 values of 8.2 and 8.3, respectively, indicating that PGD2 and the thromboxane A2 mimic probably act at the same receptor in guinea-pig tracheal smooth muscle. Contractions of guinea-pig tracheal spirals induced by PGE2 were not antagonized, and those caused by PGF2 alpha were only partially antagonized by +/- SQ 29,548. The +/- SQ 29,548 also significantly inhibited the aorta contracting activity of 11,9-epoxymethano PGH2 (pA2 = 9.1) and thromboxane A2 released from perfused guinea-pig lungs upon arachidonic acid challenge.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenylyl Cyclases↗
PubMed1984

[Treatment of esophageal cancer by endoscopic administration of peplomycin ointment].

Pepleomycin ointment was developed to improve the antitumor activity afforded by endoscopic therapy for esophageal cancer. Through the esophagoscope we could observe this ointment specifically attacking the lesion. Furthermore we were able to recognize that peplomycin was acting directly on the lymph nodes as well as the tumor in a resected portion of the esophagus. It is hopefully anticipated that this method will be used as a combination therapy in pre-operative and inoperable esophageal cancer.

Aged↗
PubMed1983

Light and electron microscopic demonstration of guanylate cyclase in rat brain.

Guanylate cyclase (GTP pyrophosphate-lyase (cyclizing), EC4.6.1.2.) was histochemically demonstrated in rat brain with light and electron microscopes by using a specific monoclonal antibody to soluble guanylate cyclase from rat brain. Under a light microscope, intense reactions were seen in caudate-putamen complex, neocortex and cerebellar cortex. Immunoreactive cells were mainly some types of neurons such as small neurons in caudate-putamen complex, Purkinje cells in cerebellar cortex and pyramidal cells in neocortex. Some astroglial cells were also stained. Not all neurons or glial cells exhibited the positive guanylate cyclase reactivity. Electron microscopic examination revealed that guanylate cyclase was localized within postsynaptic components (perikaryon and dendrites) in neurons and in the cytoplasm and plasma membrane of astroglia. Presynaptic terminals were free of reaction. The observation supports a possibility that cyclic GMP is involved in the postsynaptic events of neuronal transmission and the regulation of intracellular processes.

Animals↗
PubMed1983

Species heterogeneity of pineal hydroxyindole-O-methyltransferase.

Hydroxyindole-O-methyltransferase was purified from bovine and chicken pineal glands to apparent homogeneity and their properties were compared. The purified enzymes from both pineal glands differed in electrophoretic mobility and isoelectric point. Sodium dodecyl sulfate gel electrophoresis revealed that hydroxyindole-O-methyltransferase of both bovine and chicken pineals was a dimer consisting of a subunit of molecular weight 39,000. The two enzymes also differed in substrate specificity. Bovine hydroxyindole-O-methyltransferase showed a high specificity toward N-acetylserotonin, whereas chicken enzyme methylated N-acetylserotonin and, to some extent, serotonin and bufotenine. The methylation of the three substrates was probably catalyzed by the same enzyme of chicken pineal, because the ratio of substrate availability did not change throughout the purification steps. Using the purified enzymes, we prepared antibody to both bovine and chicken hydroxyindole-O-methyltransferase. The antibody to bovine enzyme cross-reacted with both avian and mammalian enzymes, whereas the antibody to chicken hydroxyindole-O-methyltransferase reacted with avian enzymes, but far less with mammalian enzymes, indicating an immunochemical difference between avian and mammalian hydroxyindole-O-methyltransferase. The results suggest that the properties of hydroxyindole-O-methyltransferase have changed during the evolutionary development of the pineal glands.

Acetylserotonin O-Methyltransferase↗
PubMed1983

Cellular mechanism involved in the synthesis of cyclic GMP in nervous tissues.

Intracellular cyclic GMP content responds to the stimulation of muscarinic receptor in a variety of tissues. Several aspects of the cellular mechanism involved in the synthesis of cyclic GMP were investigated. 1. In cultured bovine chromaffin cells, acetylcholine as well as muscarine stimulated the 32Pi incorporation into phosphatidic acid, induced Ca2+ mobilization across the cells, and, in parallel, elevated intracellular cyclic GMP content. Phosphatidic acid added to culture medium also stimulated the efflux and influx of Ca2+ and the synthesis of cyclic GMP in bovine chromaffin cells and in neuroblastoma cells in the same fashion as acetylcholine. 2. We have succeeded in a purification of an endogenous activator for guanylate cyclase from rat brain and identified it as L-arginine. L-Arginine, but not D-arginine, activated soluble guanylate cyclase 10- to 20-fold at a low concentration (1-2 X 10(-5) M). The activation of the enzyme by L-arginine seemed to require Ca2+. Calcium accumulated in cells in response to muscarinic stimulation would activate guanylate cyclase in collaboration with L-arginine. 3. Using a specific monoclonal antibody, we demonstrated the cellular and subcellular localizations of guanylate cyclase in rat brain. An intense reaction was observed in the brain regions which were rich in muscarinic receptor. Electron microscopic examination revealed that guanylate cyclase was concentrated in the postsynaptic perikaryon and dendrites of some type of neurons indicating its involvement in neural transmission.

Acetylcholine↗